Update code to typescript

src/tts/BaseEngine.ts

@@ -0,0 +1,56 @@
+import { writeFile } from "node:fs/promises";
+
+export type VoiceParams = Record<string, unknown>;
+
+/**
+ * Common contract for every TTS provider. Subclasses override either
+ * `getSpeech` (returning a fetch-like Response) or `getSpeechFile` (writing
+ * directly to disk) — the default `getSpeechFile` pipes `getSpeech` to a file.
+ */
+export abstract class BaseEngine {
+  /** Short ID used in env / commands (e.g. "azure"). */
+  readonly shortName: string;
+  /** Human-readable name shown in messages. */
+  readonly longName: string;
+  /** Output file extension without the dot (e.g. "mp3"). */
+  readonly fileExtension: string;
+
+  protected voices: Record<string, string | { name: string; lang: string }> = {};
+
+  constructor(shortName: string, longName: string, fileExtension: string) {
+    this.shortName = shortName;
+    this.longName = longName;
+    this.fileExtension = fileExtension;
+  }
+
+  /** Maps a user-friendly voice name to the provider's internal identifier. */
+  getInternalVoiceName(str: string): string {
+    const v = this.voices[str];
+    if (v == null) return str;
+    return typeof v === "string" ? v : v.name;
+  }
+
+  abstract getDefaultVoice(): string;
+
+  validateVoice(voice: string): boolean {
+    if (Object.keys(this.voices).length === 0) return true;
+    return this.voices[voice] != null;
+  }
+
+  /** Default implementation: subclass should override either this or getSpeechFile. */
+  async getSpeech(_text: string, _voice?: string, _params?: VoiceParams): Promise<Response> {
+    throw new Error(`${this.shortName}: getSpeech not implemented`);
+  }
+
+  async getSpeechFile(
+    text: string,
+    filepath: string,
+    voice: string = this.getDefaultVoice(),
+    params: VoiceParams = {},
+  ): Promise<string> {
+    const data = await this.getSpeech(text, voice, params);
+    const buf = Buffer.from(await data.arrayBuffer());
+    await writeFile(filepath, buf);
+    return filepath;
+  }
+}